TY - JOUR
T1 - Luminescent tricarbonylrhenium(I) dipyridoquinoxaline indole complexes as sensitive probes for indole-binding proteins
AU - Lo, Kenneth Kam-Wing
AU - Sze, Ka-Shing
AU - Tsang, Keith Hing-Kit
AU - Zhu, Nianyong
PY - 2007/7/2
Y1 - 2007/7/2
N2 - Luminescent tricarbonylrhenium(I) dipyridoquinoxaline indole complexes [Re(N-N)(CO)3(L)](CF3-SO3) (N-N = dipyrido[3,2-f:2′,3′-h]quinoxaline (dpq), L = N-(3-pyridoyl) tryptamine (py-3-CONHC2H4-indole) (1a), N-(N-(3-pyridoyl)-6-aminohexanoyl)tryptamine (py-3-CONHC5H 10CONHC2H4-indole) (1b); N-N = 2-(n-butylamido)dipyrido[3,2-f:2′,3′-h]quinoxaline (dpqa), L = py-3-CONHC2H4-indole (2a), py-3-CONHC5H 10CONHC2H4-indole (2b)) and their indole-free counterparts [Re(N-N)(CO)3(py-3-CONH-Et)](CF3SO 3) (py-3-CONH-Et = N-ethyl-(3-pyridyl)formamide; N-N = dpq (1c), dpqa (2c)) have been synthesized and characterized. The crystal structure of a related complex, [Re(dpqa)(CO)3-(pyridine)](PF6), has also been studied. All the complexes exhibited triplet metal-to-ligand charge-transfer (3MLCT) (dπ(Re) → π*(N-N)) emission in fluid solutions at 298 K and in alcohol glass at 77 K. The emission quantum yields of the complexes were reduced upon changing from CH2Cl 2 to aqueous buffer. The reduction was much more significant for the dpqa complexes than the dpq complexes due to the hydrogen-bonding interaction of the amide substituent of the dpqa ligand with water molecules. The interactions of these tricarbonylrhenium(I) complexes with indole-binding proteins including bovine serum albumin and tryptophanase have been studied by emission titrations and inhibition assays, respectively. © 2007 American Chemical Society.
AB - Luminescent tricarbonylrhenium(I) dipyridoquinoxaline indole complexes [Re(N-N)(CO)3(L)](CF3-SO3) (N-N = dipyrido[3,2-f:2′,3′-h]quinoxaline (dpq), L = N-(3-pyridoyl) tryptamine (py-3-CONHC2H4-indole) (1a), N-(N-(3-pyridoyl)-6-aminohexanoyl)tryptamine (py-3-CONHC5H 10CONHC2H4-indole) (1b); N-N = 2-(n-butylamido)dipyrido[3,2-f:2′,3′-h]quinoxaline (dpqa), L = py-3-CONHC2H4-indole (2a), py-3-CONHC5H 10CONHC2H4-indole (2b)) and their indole-free counterparts [Re(N-N)(CO)3(py-3-CONH-Et)](CF3SO 3) (py-3-CONH-Et = N-ethyl-(3-pyridyl)formamide; N-N = dpq (1c), dpqa (2c)) have been synthesized and characterized. The crystal structure of a related complex, [Re(dpqa)(CO)3-(pyridine)](PF6), has also been studied. All the complexes exhibited triplet metal-to-ligand charge-transfer (3MLCT) (dπ(Re) → π*(N-N)) emission in fluid solutions at 298 K and in alcohol glass at 77 K. The emission quantum yields of the complexes were reduced upon changing from CH2Cl 2 to aqueous buffer. The reduction was much more significant for the dpqa complexes than the dpq complexes due to the hydrogen-bonding interaction of the amide substituent of the dpqa ligand with water molecules. The interactions of these tricarbonylrhenium(I) complexes with indole-binding proteins including bovine serum albumin and tryptophanase have been studied by emission titrations and inhibition assays, respectively. © 2007 American Chemical Society.
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U2 - 10.1021/om0700617
DO - 10.1021/om0700617
M3 - RGC 21 - Publication in refereed journal
SN - 0276-7333
VL - 26
SP - 3440
EP - 3447
JO - Organometallics
JF - Organometallics
IS - 14
ER -
